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Biomedical subjects

B Green

Publications and source records attributed to B Green.

At least 145 records · Page 8Linked to original sources
PubMed1988

Why the assay of serum cystine by protein precipitation and chromatography should be abandoned.

The higher bias of serum cystine estimations by a HPLC method compared with those by ion exchange techniques is shown to be largely due to differences in the sample preparation procedures of the two techniques. The ion exchange methods utilised sulphosalicylic acid serum protein precipitation and post-column ninhydrin derivatisation of cystine, whilst the high pressure liquid chromatography technique employed automated dialysis for removal of proteins and pre-column ortho-phthalaldehyde derivatisation of cystine after its conversion to cysteine and then to S-carboxymethylcysteine. Examination of these procedures showed that whilst the high pressure liquid chromatographic method accurately estimates total serum cystine and cysteine, many factors affect the precision and accuracy of serum cystine estimations using the ion exchange techniques. In particular, serum protein precipitation techniques that are currently employed for the preparation of samples for cystine analysis by ion exchange chromatography should be abandoned.

Blood Proteins↗
PubMed1987

Effect of injury on nerve growth factor uptake by sensory ganglia.

The level of the nerve growth factor protein, NGF, in vivo has a profound influence on axonal sprouting by sensory neurons of vertebrate dorsal root ganglia. There is evidence also that NGF may play similar roles in cholinergic central structures in brain. In both instances, retrograde transport of NGF has been demonstrated. Here we examined uptake of NGF by DRG neurons in response to contusion injury of the spinal cord. Under these conditions there was uptake and transport of NGF into large DRG neurons via central processes but no uptake by non-DRG central neurons. Thus, any effects of NGF on spinal neurons or their processes would be secondary to the direct effects of NGF on DRG neurons.

Animals↗
PubMed1987

Changes in milk carbohydrates during lactation in the eastern quoll, Dasyurus viverrinus (Marsupialia).

1. Milk samples were obtained at various stages of lactation from 16 captive eastern quolls. 2. The mean milk carbohydrate concentration was 7.4% (w/v; total hexose) at 8 weeks post partum, decreasing to 5.2% at 17 weeks and to less than 2% at the end of lactation. 3. The predominant monosaccharide constituent of the carbohydrates was galactose, followed by glucosamine, glucose and sialic acid. 4. Thin layer and gel chromatography showed that the milk carbohydrates consisted of lactose and a variety of higher oligosaccharides, some of which appeared to be identical to oligosaccharides of known structure previously isolated from milk of the tammar wallaby, Macropus eugenii. 5. In general, both the quantitative and qualitative changes observed in the milk carbohydrates of the eastern quoll were similar to those documented for macropodids.

Animals↗
PubMed1987

Milk composition in the eastern quoll, Dasyurus viverrinus (Marsupialia:Dasyuridae).

The milk constituents of Dasyurus viverrinus, a carnivorous marsupial, exhibited major quantitative and qualitative changes during the course of lactation. The milk produced in the early stages of lactation was dilute, about 13-16% (w/w) solids before 3 weeks with carbohydrate representing the major fraction. In the latter stages of lactation the milk was concentrated, around 30% solids, and lipid was the predominant fraction. Palmitic acid was the major fatty acid present in early-stage milk but oleic acid became predominant in milk after 10 weeks post-partum. The changes in milk composition in D. viverrinus were similar to those described for the milks of herbivorous marsupials which therefore suggests that this pattern may be uniform throughout the Marsupialia.

Animals↗
PubMed1986

Cardiovascular findings in quadriplegic and paraplegic patients and in normal subjects.

Seven normal, 7 paraplegic and 7 quadriplegic patients underwent cross-sectional cardiovascular evaluation, including recording of sitting heart rate, blood pressure and echocardiography. Quadriplegic patients had a 26% lower left ventricular (LV) mass index (75 +/- 13 g/m2, p less than 0.01) compared with normal volunteers (102 +/- 16 g/m2) or paraplegic patients (110 +/- 26 g/m2). Six quadriplegic patients and 3 paraplegic patients had an unusual pattern of LV posterior wall asynergy, which was associated with a significant rightward shift of the frontal-plane QRS axis (92 +/- 22 degrees vs 42 +/- 41 degrees, p less than 0.005) and smaller left atrial dimensions (2.4 +/- 0.4 vs 3.0 +/- 0.3 cm, p less than 0.005). The quadriplegic group was characterized by a significantly reduced mean blood pressure (67 +/- 7 vs 88 +/- 8 mm Hg in normal subjects, p less than 0.002), high normal peripheral resistances (22 +/- 5 vs 17 +/- 5 units in normal subjects, difference not significant) and a markedly reduced calculated cardiac output (3.2 +/- 0.6 vs 5.4 +/- 1.4 liters/min in normal subjects, p less than 0.01). Hemodynamic data for the paraplegic patients were similar to those in the normal group. A decrease in LV wall stress, mediated primarily by a decrease in venous return, appeared to result in the "adaptive" cardiac atrophy seen in these quadriplegic patients. LV asynergy was common and also may be related to a decrease in cardiac filling.

Adolescent↗
PubMed1986

Spinal cord tumors presenting with neural tube defects.

Two primary lumbosacral tumors arising at the site of neural tube defects are presented. One was a teratoma diagnosed in an infant with myelomeningocele. The other was an ependymoma that developed in an adult with meningocele. It is postulated that these cases represent a neoplastic transformation of heterotopic primordial elements that have been incorporated within the defect, supporting the view that overgrowth of neural tissue may be the result rather than the cause of neural tube deformity. Such rare occurrences may be due to interaction between intrauterine teratogenic factors and familial predisposition in affected patients.

Adult↗
PubMed1985

Intake of milk by suckling echidnas (Tachyglossus aculeatus).

Estimation of milk intake in the sucklings of three captive echnidnas, Tachyglossus aculeatus, and in one living in its natural habitat were made by determination of sodium turnover rate and sodium content of the milk. The mean rate of sodium influx of the sucklings was 2.48 +/- 1.31 mmol/kg X day. The daily rates of milk consumption and growth rates were variable with a mean weight increment of 0.41 +/- 0.10 g for each ml of milk consumed. There is a wide disparity in growth rates of echidna young that is related to differences in the body weights of the mothers.

Aging↗
PubMed1985

Risk factors for early neonatal sepsis.

The authors undertook a case-control study of 113 cases of neonatal sepsis and 347 randomly selected controls. All cases and controls were selected from the 1980 and 1981 Washington State birth certificates. The increased risk for males (odds ratio (OR) = 1.75, p = 0.012) and the large risk associated with low birth weight (OR = 99.1, p less than 0.001 if less than 1,500 g and OR = 5.17, p less than 0.001 if 1,500-2,500 g) are consistent with past studies. The relationship of maternal age (OR = 2.00, p = 0.01 if less than or equal to 20 years and OR = 1.74, p = 0.05 if greater than 30) parallels the overall risk of many pregnancy-related complications in these age groups. Interpretation of the elevated risk associated with amniocentesis is hampered by small numbers but is provocative. The strong association of an Apgar score of 6 or less at five minutes (OR = 36.25, p less than 0.001) with neonatal sepsis suggests the possibility of routine sepsis evaluation in such neonates born in areas with high incidence rates of early neonatal sepsis. We found no previous reports associating either abruptio placentae (OR = 12.70, p = 0.028) or preeclampsia (OR = 6.43, p = 0.017) with neonatal sepsis.

Abruptio Placentae↗
PubMed1984

Cervical sagittal spinal canal size in spine injury.

This study investigated the relationship between cervical spine sagittal canal diameter and neurologic injury in cases of spinal fracture-dislocation. A group of 98 patients with such injuries was reviewed; 45 had no neurologic deficits, 39 had incomplete quadriplegia, and 14 had complete quadriplegia. Spinal canal sagittal diameter was measured in all, and large diameter and small canals were defined. Small diameter canals were correlated significantly with neurologic injury, while large diameter canals allowed protection from neurologic injury in cervical fracture dislocation.

Adult↗
PubMed1984

The plasma concentration of medroxyprogesterone acetate and ovarian function during treatment with medroxyprogesterone acetate in 5 and 10 mg doses.

Peripheral plasma levels of medroxyprogesterone acetate (MPA) were determined by radioimmunoassay in 5 women after oral administration of 5 and 10 mg medroxyprogesterone acetate daily. Peak levels of MPA in plasma were recorded within 1 - 3 hours of taking the tablet, which indicates a rapid absorption from the gastro-intestinal tract. The levels of medroxyprogesterone acetate 12 hours after taking of the 5 mg tablet remained constant throughout the 8 weeks of study. Peripheral plasma levels of estradiol and progesterone were determined throughout treatment. The estradiol levels indicated development of follicles in 7 out of 10 treatment months in the 5 mg group, and in 3 of the subjects treated with 10 mg MPA. The progesterone levels in those women treated with 5 mg MPA showed normal luteal concentration values in 2 out of 10 treatment months. No woman treated with 10 mg MPA had an increase in progesterone during the 21-day period of treatment. The results obtained in this study suggest that 10 mg MPA daily will inhibit ovulation but 5 mg is not sufficient to inhibit ovulation in all women.

Administration, Oral↗
PubMed1983

Qualitative and quantitative changes in milk fat during lactation in the tammar wallaby (Macropus eugenii).

There are major quantitative and qualitative changes in the milk lipids during lactation in the tammar wallaby, Macropus eugenii. The crude lipid content of the milk is relatively low during the first 10 weeks of lactation; between 10 and 26 weeks post partum the lipid content increases gradually but after that it increases rapidly. The triglyceride fraction of the lipid at early stages of lactation contains a large amount of palmitic acid and relatively little oleic acid whereas mature milk exhibits little palmitic and much oleic acid. In the early stages of lactation fat represents 15% of the total solids and carbohydrate 55%; around 26-30 weeks post partum the carbohydrate moiety falls sharply to a level less than 2% of the solids while lipids increase to c. 60% of the solids. These changes coincide with increases in milk solids, emergence of the young from the pouch, ingestion of herbage, and fermentation of cellulose in the stomach.

Animals↗